Image processing apparatus, image processing method, and recording medium storing a program

ABSTRACT

An image processing apparatus includes an image-area separator that separates a character area from monochrome document data scanned by a scanner, a character pixel detecting unit that counts the number of pixels of a character in the main scanning direction and the sub-scanning direction included in a controller, a bolded character identifying unit that identifies a character as a bolded character in case the count result is larger than a predefined threshold value, and a color converter that converts the bolded character into color data.

CROSS-REFERENCE TO RELATED APPLICATION

This patent application is based on and claims priority pursuant to 35U.S.C. §119 to Japanese Patent Application No. 2012-180630, filed onAug. 16, 2012 in the Japan Patent Office, the entire disclosure of whichis hereby incorporated by reference herein.

BACKGROUND

1. Technical Field

The present invention relates to an image processing apparatus, imageprocessing method, and recording medium storing a program.

2. Background Art

Conventionally, in the case of printing monochrome electronic data,copying monochrome documents, and distributing them, there is demand forprinting the monochrome data partially in color such as a highlightpoint to make an important part clear.

To satisfy this kind of demand, a technology that detects gradation of amonochrome document, adds color information to the document depending onthe gradation, and which prints even monochrome documents in color, hasbeen proposed (e.g., JP-H10-324025-A.) However, one problem is thatbolded characters are not colorized, making it difficult to identify thebolded characters.

SUMMARY

The present invention provides an improved image processing apparatusthat includes an image-area separator that separates a character areafrom a monochrome document, a bolded character identifying unit thatidentifies the character area as a bolded character in case the numberof pixels in the separated character area is larger than a predefinedvalue, and a color converter that converts the bolded character into acolor image in case the character area is identified as the boldedcharacter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings.

FIG. 1 is a block diagram illustrating a configuration of an imageprocessing apparatus as an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a process executed in an embodimentof the present invention.

FIGS. 3A and 3B are diagrams illustrating a process performed by acharacter pixel detecting unit and a bolded character identifying unitas an embodiment of the present invention.

FIGS. 4A, 4B, and 4C are diagrams illustrating a process executed by acolor converter that identifies whether or not bolded characterinformation is converted into color information as an embodiment of thepresent invention.

FIGS. 5A and 5B are flowcharts illustrating a process executed by thecolor converter as an embodiment of the present invention.

FIG. 6 is a diagram illustrating a preview display as an embodiment ofthe present invention.

FIG. 7 is a diagram illustrating an example of changing a thresholdvalue for identifying a bolded character in accordance with fontinformation and font size as an embodiment of the present invention.

FIGS. 8A and 8B are diagrams illustrating an example of a characteridentifying method as an embodiment of the present invention.

DETAILED DESCRIPTION

In describing preferred embodiments illustrated in the drawings,specific terminology is employed for the sake of clarity. However, thedisclosure of this patent specification is not intended to be limited tothe specific terminology so selected, and it is to be understood thateach specific element includes all technical equivalents that have thesame function, operate in a similar manner, and achieve a similarresult.

To cope with the above problem, the present invention provides an imageprocessing apparatus that colorizes a bolded character part (emphaticpart) and makes it easy to identify that part. In a process ofcolorizing a monochrome document, the image processing apparatus of thepresent invention identifies weight of a character in the monochromedocument, identifies an area to be color-converted among boldedcharacters depending on a characteristic of the document such as layout,and performs color conversion.

FIG. 1 is a block diagram illustrating a configuration of an imageprocessing apparatus. Shown in FIG. 1 are a scanner 101 that scans amonochrome document, a RGB gamma convertor 102 that performs a gammaconversion process on the scanned data, a filter processer 103 thatperforms an edge emphasizing process and a smoothing process, a colorconverter 104 that converts the identified bolded character into colordata, a CMYK gamma converter 105 that performs gamma conversion processon the color data, a gradation processor 106 that converts a multivaticimage into a less-valued image, a printer engine 107 that forms animage, an image-area separator 108 that identifies a character, a photo,and blank from the scanned data, and a controller 109. The controller109 includes units such as a character pixel detecting unit 110 thatcounts the number of pixels of a character, a bolded characteridentifying unit 111 that identifies a character as a bolded characterin case the number of pixels of the character is larger than apredefined threshold value, a page number detecting unit 112 thatdetects a page number that includes a bolded character, a boldedcharacter location identifying unit 113 that identifies location of abolded character in a page, a surrounding information identifying unit114 that identifies surrounding information of a bolded character, afont type identifying unit 115 that identifies a font type, and acharacter size identifying unit 116 that identifies a character size. Innormal copy operation, the color converter 104 converts RGB data intoCMYK data.

After the image-area separator 108 performs a separating process on themonochrome document data scanned by the scanner 101, the area identifiedas a character is input into the controller 109. The character pixeldetecting unit 110 in the controller 109 counts the number of pixels inthe main scanning direction, the sub-scanning direction, and thediagonal direction of the character. The bolded character identifyingunit 111 identifies the character as a bolded character in case thecount obtained by the character pixel detecting unit 110 is larger thana predefined threshold value. The color converter 104 converts thebolded character part into color data (e.g., red).

FIG. 2 is a flowchart illustrating a process executed in thisembodiment. After starting functions such as copying, scanning, andprinting, the image-area separator 108 determines whether or not a colorconversion mode (a function that colorizes a bolded character in amonochrome document) is selected (201). If the color conversion mode isselected (YES in 201), the image-area separator 108 detects whether ornot there is character information in the document (202). If there is nocharacter, a normal copy operation is performed (208). If there is acharacter, the character pixel detecting unit 110 counts the number ofpixels in the character area in the main scanning direction and thesub-scanning direction (203). After performing the same process on allcharacter areas in the whole page, a standard number of pixels(threshold value) for normal characters (standard characters) used inthe document is identified (204). Subsequently, the bolded characteridentifying unit 111 determines whether or not there is a characterlarger than the standard number of pixels (a character with differentweight) in the document (205). If there is a target character, the colorconverter 104 performs color information conversion process on thespecified character area (206), and the image is output (207).

FIGS. 3A and 3B are diagrams illustrating a process performed by thecharacter pixel detecting unit 110 and the bolded character identifyingunit 111. As shown in FIG. 3A, the character pixel detecting unit 110counts the number of pixels for the area recognized as the characterarea in the main scanning direction and the sub-scanning direction andcounts the number of pixels in black area regarding points where datachanges from white (255) to black (0) rapidly in each scanningdirection.

Taking the number of pixels of the standard character in the mainscanning direction and the sub-scanning direction as the thresholdvalue, the bolded character identifying unit 111 identifies a characterwhose number of pixels in the main scanning direction and thesub-scanning direction is larger than the threshold value as a boldedcharacter.

Here, as shown in FIG. 3B, after counting the number of pixels in themain scanning direction and the sub-scanning direction at the samepoint, if the number of pixels in the main scanning direction and thesub-scanning direction is not the same, it is determined that thecounting is performed at a horizontal line area (or a vertical linearea). In that case, it is necessary to count at an area where such casedoes not occur or to adopt one with fewer pixels.

FIGS. 4A, 4B, and 4C are diagrams illustrating a process executed by thecolor converter that determines whether or not bolded characterinformation is converted into color information. FIG. 4A illustrates anidentification result indicating that the bolded character locationidentifying unit 113 identifies a location of the bolded character in adocument page. FIG. 4B illustrates an identification result indicatingthat the surrounding information identifying unit 114 identifiesinformation surrounding the bolded character. FIG. 4C illustrates adetection result indicating that the page number detecting unit 112detects the page number that includes the bolded character.

Using a combination of the results illustrated in FIGS. 4A, 4B, and 4C,the color converter 104 identifies whether or not the target boldedcharacter is to be converted into color information. Several specificexamples are described in detail below.

If the location of the bolded character is “circled number 1”, “C” and“α”, the conversion of the color information is not performed since itis probable that the target bolded character is a title written on thefront cover.

If the bolded character is located at from circled number 2 to circlednumber 7, the conversion of the color information is not performed sinceit is probable that the target bolded character is a header or footer.If the bolded characters exist at the same location in both “α” and “β”in addition to from circled number 2 to circled number 7, the conversionof the color information is not performed since it is probably a headeror footer.

If the bolded character is located at from circled number 1 to circlednumber 7 and the surrounding information in all directions is “A”, theconversion of the color information is performed regardless of otherconditions. If the bolded character is located at circled number 8 andthe surrounding information is “B”, the conversion of the colorinformation is not performed since it is probable that it is a captionof a photo or a chart, a name of a table, or a name of a chart. In othercases, the conversion of the color information is performed. Asdescribed above, it is possible to change color of specific boldedcharacters, and unintentional color conversion is not performed.

FIGS. 5A and 5B are flowcharts illustrating a process executed by thecolor converter. If there is a bolded character (YES in 301), thelocation of the bolded character in the document is identified first(303).

(1) In Case the Bolded Character is Located at Center.

After identifying the page information (304), if the bolded character islocated on the first page, the image information surrounding the boldedcharacter is identified (305). If there is a character in thesurrounding area, it is determined that the bolded character is locatedin text, and the color conversion is performed (306). If there is aphoto or blank in the surrounding area, it is determined that the boldedcharacter is in the title of the document written on the front cover,and the color conversion is not performed (307 and 308).

If the bolded character is located on the second page or later (304),the image information surrounding the bolded character is identified(309). If there is a character or blank in the surrounding area, thecolor conversion for the bolded character is performed (310 and 314). Ifthere is a photo in the surrounding area, it is determined whether ornot there is a character in the further surrounding area (e.g., in anydirection on the left, right, top, and bottom) (311). If there is acharacter in the surrounding area, the color conversion for the boldedcharacter is performed since it is probable the bolded character existsin text (313). If there is no character in the surrounding area of thebolded character, the color conversion for the bolded character is notperformed since it is probable that the bolded character is in text thatexplains the photo or name of the photo (312).

(2) In Case the Bolded Character is Located at any of Upper Left, UpperCenter, Upper Right, Lower Left, Lower Center, or Lower Right

After identifying the page information (315), if the bolded character islocated on the first page, the image information surrounding the boldedcharacter is identified (318). If there is a character in thesurrounding area, it is determined that the bolded character is locatedin text, and the color conversion is performed (319). If there is blankin the surrounding area, it is determined that the bolded character isin the header or footer, and the color conversion is not performed(323). If there is a photo in the surrounding area, it is determinedwhether or not there is a character in the further surrounding area(320). If there is a character in the surrounding area, the colorconversion for the bolded character is performed since it is probablethe bolded character exists in text (322). If there is no character inthe surrounding area of the bolded character, the color conversion forthe bolded character is not performed since it is probable that thebolded character is in text that explains the photo or name of the photo(321).

If the bolded character is also located on the second page or later(315), the location of the bolded character on the first page iscompared with the location of the bolded character on the second page orlater. After the comparison, if the location of the bolded character onthe first page corresponds with the location of the bolded character onthe second page or later (YES in 316), it is determined that the boldedcharacter is in the header or footer, and the color conversion is notperformed (317) If the location of the bolded character on the firstpage does not correspond with the location of the bolded character onthe second page or later (NO in 316), the same process as the boldedcharacter exists on the first page is performed.

(3) Other Cases

The surrounding information is identified since there is no need tocheck the page number (324). If there is a character or blank in thesurrounding area, the color conversion of the bolded character isperformed (325 and 329). If there is a photo in the surrounding area, itis determined whether or not there is a character in the furthersurrounding area (e.g., in any direction on the left, right, top, andbottom) (326). If there is a character in the surrounding area, thecolor conversion for the bolded character is performed since it isprobable that the bolded character exists in text (328). If there is nocharacter in the surrounding area of the bolded character, the colorconversion for the bolded character is not performed since it isprobable that the bolded character is in text that explains the photo orname of the photo (327).

As described above, it is determined whether or not the color of thebolded character is changed. It is no problem to change the aboveidentification (whether or not the color conversion is performed)appropriately in accordance with the situation.

FIG. 6 is a diagram illustrating a preview display. As shown in FIG. 6,it is possible to check whether or not the color conversion has beenperformed as intended before printing by displaying a preview of theconverted part on the display of the image processing apparatus. In FIG.6, the color conversion is performed on the area surrounded by thebroken line, and it is easy to recognize the color-converted partvisually by changing the color on the preview actually or by flashing,etc. Consequently, if an area is color-converted unintentionally, it ispossible to modify that. Also, by pressing a change color button, it ispossible to change the color to be replaced. Furthermore, it is possibleto change the color further in a specific area.

FIG. 7 is a diagram illustrating an example of changing a thresholdvalue for identifying a bolded character in accordance with fontinformation and font size.

If it is possible to acquire font information, font weight differsdepending on a font typeface (sans serif or roman) as shown in FIG. 7.Therefore, if it is possible to acquire font information, the font typeidentifying unit 115 changes a threshold value in counting pixels foridentifying a bolded character in accordance with the font typeface. Itshould be noted that the character size identifying unit 116 changes athreshold value in counting pixels for identifying a bolded character inaccordance with font size, since font weight differs depending on fontsize, thereby improving detection accuracy of bolded characters.

FIGS. 8A and 8B are diagrams illustrating an example of a characteridentifying method. If font weight is too fat, it is determined that thearea is a photo area in processing an image in some cases. To avoid thatproblem, it is determined that the area is a character area depending onsurrounding information even if the target area is a photo area, andcolor conversion is performed.

As shown in FIG. 8A, if an area surrounded by character information isidentified as a photo area, the area is identified as a character areasince it is considered very rare that a photo area is located at suchposition, and color conversion is performed if needed. Similarly, asshown in FIG. 8B, while the area identified as a photo area issurrounded by character information, there are two rows of characterareas on the left and right of the photo area. In this case, the photoarea is treated as a photo area, and color conversion is not performed.

The present invention can also be implemented by providing a storagemedium storing software program code that implements functions of theembodiment described above to a system or an apparatus and reading andexecuting the program code stored in the storage medium by a computer (aCPU or MPU) in the system or apparatus. In this case, the program coderead from the storage medium itself implements functions in theembodiment described above. A hard disk, an optical disk, amagneto-optical disk, a nonvolatile memory card, and a ROM can be usedas the storage medium to provide the program code. The present inventionincludes not only implementing functions in the embodiment describedabove by executing the read program code by the computer but alsoimplementing functions of the embodiment described above by executingpart or all of the above-described processes by an Operating System (OS)run on the computer based on the program code. Furthermore, after theprogram code read from the storage medium is written in memory includedin a function expansion board inserted into the computer or a functionexpansion unit connected to the computer, the CPU in the functionexpansion board or the function expansion unit executing a part or allof an actual process based on commands of the program code andimplements functions in the embodiment described above by the process isalso included within the present invention. The program that implementsfunctions of the embodiment can be provided from a server via acommunication network.

Numerous additional modifications and variations are possible in lightof the above teachings. It is therefore to be understood that, withinthe scope of the appended claims, the disclosure of this patentspecification may be practiced otherwise than as specifically describedherein.

As can be appreciated by those skilled in the computer arts, thisinvention may be implemented as convenient using a conventionalgeneral-purpose digital computer programmed according to the teachingsof the present specification. Appropriate software coding can readily beprepared by skilled programmers based on the teachings of the presentdisclosure, as will be apparent to those skilled in the software arts.The present invention may also be implemented by the preparation ofapplication-specific integrated circuits or by interconnecting anappropriate network of conventional component circuits, as will bereadily apparent to those skilled in the relevant art.

What is claimed is:
 1. An image processing apparatus, comprising: animage-area separator to separate a character area from a monochromedocument; a bolded character identifying unit to identify the characterarea as a bolded character in case the number of pixels in the separatedcharacter area is larger than a threshold value; and a color converterto convert the bolded character into a color image in case the characterarea is identified as a bolded character.
 2. The image processingapparatus according to claim 1, further comprising: a bolded characterlocation identifying unit to identify the location of the boldedcharacter in a page of the document; a surrounding informationidentifying unit to identify information on the area surrounding thebolded character; and a page number detecting unit to detect a pagenumber that includes the bolded character; wherein the color converterrefers to identification results obtained by the bolded characterlocation identifying unit and the surrounding information identifyingunit and the detection result obtained by the page number detecting unitin converting the bolded character into a color image.
 3. The imageprocessing apparatus according to claim 2, wherein the color converterperforms color conversion in case the bolded character is located at thecenter of the document, the page number is one, and the surroundinginformation of the bolded character is a character; and does not performcolor conversion in case the surrounding information of the boldedcharacter is not a character.
 4. The image processing apparatusaccording to claim 2, wherein the color converter performs colorconversion in case the bolded character is located at any of the upperright, upper center, upper left, lower right, lower center, or lowerleft of the document, the page number is one, and the surroundinginformation of the bolded character is character and does not performcolor conversion in case the surrounding information of the boldedcharacter is blank.
 5. The image processing apparatus according to claim2, wherein the color converter does not perform color conversion in casethe bolded character is located at any of the upper right, upper center,upper left, lower right, lower center, or lower left of the document,the page number is not one, and the location of the bolded character onthe page one matches the location of the bolded character on the pagetwo or a subsequent page.
 6. The image processing apparatus according toclaim 1, further comprising a font type identifying unit that identifiesfont type, wherein the threshold value is changed in accordance with theidentified font type.
 7. The image processing apparatus according toclaim 1, further comprises a font size identifying unit that identifiesfont size, wherein the threshold value is changed in accordance with theidentified font size.
 8. A method of processing an image, comprising thesteps of: separating a character area from a monochrome document;identifying the character area as a bolded character in case the numberof pixels in the separated character area is larger than a predefinedvalue; and converting the bolded character into a color image in casethe character area is identified as a bolded character.
 9. Anon-transitory recording medium storing a program that, when executed bya computer, causes the computer to implement a method of processing animage, the method comprising the steps of: separating a character areafrom a monochrome document; identifying the character area as a boldedcharacter in case the number of pixels in the separated character areais larger than a predefined value; and converting the bolded characterinto a color image in case the character area is identified as a boldedcharacter.